Grate



.Jan. 11 Q 1927.

O. .W. PETERSEN GRATE c 10, 1921 I5- vSheets-Sheet 1 Jan. 11 1927.

o. w. PETERSEN GRATE Filed Dec. 10, 1921 I5 Sheets-Sheet 2 W ww Jan; 11,1927.

Y O. W. PETERSEN GRATE Filed Dec. 10, 1921 :5 Shets-Sheet Patented Jan. 11, 1927.

warren STATES PATENT OFFHIE.

OLAF W. PETERSEN, OF. BUFFALO, NEVI YORK, ASSIGNGR TO VOGT BROTHERS MFG. CCL,

F LOUISVILLE, KENTUCKY. I

GRATE.

Application filed December 1 1921.

This invention relates to grates of the kind by means of which the fuel, during the combustion thereof, canbe advanced in the direction of the length of the grate.

The objects of the invention are to provide a grate of this kind of improved construction comprising alternately arranged movable and stationary grate members which are so arrange d relatively to each other that the fuel can be positively pushed by the movable grate members across the fuel supporting surfaces of the stationary grate members; also to provide a grate of this kind in which the bearings or pivots of the movable members are arranged below the fuel supporting surface of the grate in such a manner as to permit parts of the movable grate members to pass over the stationary grate members and so that the bearings or pivots are removed from the destructive heat of the fire; also to provide movable grate members which are adapted to be constructed in sections to eliminate warping of the grate members and to facilitate the replacing or repair of the movable grate members; also to provide a grate of this kind which is so arranged that the fuel will be distributed evenly over the grate surface in a relatively thin layer, thereby assuring uniform and complete combustion of the fuel also to improve the construction f grates of this kind in other respects hereinafter specified.

in the accompanying drawings:

Fig. 1 is a top plan view of a grate embodying the invention.

Fig. 2 is a side elevation'thereof.

Figs. 3 and 4 are longitudinal sectional elevations thereof, showing the movable members in different positions. Fig. 5 is a fragmentary longitudinal sectional view thereof showing the arrangement of the removable sections of the removable grate members.

6 is a perspective view of a removable element or unit of a movable grate member.

7 and 8 are fragmentary transverse syiional elevations thereof on lines 7-7, Fig. 3, and 8-8, Fig. 2, respectively.

U13. 9 is a perspective view of aremovable element of one of the stationary grate members, showing the same in position to be mounted on its supporting bar.

The grate includes longitudinal support- Serial No. 521,499.

ing bars or membersA, the ends of which are supported on the walls of the furnace, or in any other suitable manner. In the construction shown, the rear end of the grate is embedded in the rear wall of the furnace and the front end issugported on an angle shaped portion or extension at of the dead plate at, extending transversely of the front of the furnace The several parts of the grate are mounted on these supporting bars and for this purpose the bars are provided with recesses a? and a which are adapted to receive parts of the grate. The supporting bars A are preferably hollowed out at a for the purpose of lightening the same. Supporting bars of any other kind maybe provided if desired.

The grate includes alternately arranged movable and stationary grate bars or mem bers which extend transversely of the grate, those shown being supported at their opposite ends on the supporting bars A and the movable grate bars are so arranged as to swing over or across the upper surface of the stationary grate bars and to push the fire over the stationary bars lengthwise of the grate. The stationary grate bars may be of any suitable or desired construction, those shown including transverse supporting members or bars B having end portions I) which are formed 'to'enter into the slots a? of the longitudinal supporting bars. The bars B are adapted to receive a plurality of fire supporting units or elements C. see particularly Fig. 9. which are provided with upper, substantially flat fire supporting surfaces 0 having recesses c in the sides thereof, through which the air may pass to the fire from beneath the grate and through which ash may drop. The fire supporting elements are also provided with downwardly extending legs 0 adapted to straddle the bar 13 for holding the elements in correct relation in the grate. One of the legs 0 is preferably provided on its inner surface with a transverse notch or groove 0 adapted to cooperate with a head 0 extending lengthwise of the transverse supporting bar B. This bead or rib c preferably terminates at a short distance from the end of the transverse bar so that the fire supporting elements may be moved vertieally into operative relation to the grate bar B at the portion thereof beyond the end of the bead a and may then be moved til) lengthwise of the bar to cause the bead 0 to engage with the groove or notch c in the leg of the fire supporting element or member. In this manner the stationary bars can be made in sections or units which can be readily replaced when damaged. The stationary grate bars may be of any other suitable or desired construction.

The movable grate bars or members of the grate are arranged between the stationary grate members in such a manner that each movable member may s ving into a position over the stationary member located in rear thereof. In order to enable the movable members to swing in this manner, the movable members are pivoted to swing about axes arranged underneath the stationary grate bars. in the particular embodiment of the invention shown for this purpose, each movable grate member is mounted upon a transversely extending pivot rod D, portions (Z of which are rotatably arranged in the lower ends or bottom portions of the slots a on the longitudinal supporting bars A. By means of this arrangement the end portions 3) of the stationary grate bars serve to hold the pivot portions of the movable bars in the slots. The intermediate portions of the rods D are preferably square in cross section and in the construction shown, a number of supporting arms E are secured to the intermediate portions of the transverse pivot rods D. Each of the supporting arms shown includes a hub portion a through which the pivot rod 1) extends and from which an arm 61- extends outwardly. The outer end of the arm 6 has an arc shaped extension or portion 6 the outer end 6 of which forms a part of the fire supporting grate surface. The lire supporting end 6 when the movable grate bar is in its normal position, is substantially on the same level with the upper surfaces of the stationary grate bars and forms with these surfaces a substantially l'lat grate surface; The fire supporting ends 0" of the arms are provided with recesses or grooves a c in the sides thereof throi 511 which air may pass from below the p to the lire, and through which asl ies may drop to the ash pit.

The supporting arms in for the movable grate member are spaced apart and the spaces between the adjacent arms are occupied by fire supporting and advancing inen1- bers which may be of any suitable or desired construction, those shown including a plurality of fire supporting units or elements 1, each of which is provided with an arc shaped portion f which corresponds substantially to the portion 6 of the support ing arm E, and with a fire supporting face or portion f which corresponds to the poi" tion 6'' of the supporting arms. These fire supporting units are arranged side by side and are connected with the arms E by means of rods or bars G G removably secured in the holes in the arms E and extending through holes 9 g in the fire supporting units. Consequently, the units F and the ends of the arms E form the movable grate bar, and in case any of these units become damaged, they can be readily replaced by removing the rods G G so as to permit the tire supporting units to be removed and replaced by others. Each of the fire supporting units of the movable grate bars is also provided in its sides with channels or grooves f and the segmental portion of each tire supporting unit is also preferably provided in its side with depressions f" which grooves and depressions permit the air to pass freely to the fire and ashes to drop to the ash pit. A movable grate member of other construction may be used, if desired.

By providing the movable grate bar with an arc shaped front end portion formed by the parts a and f of the supporting arms arrl lire supporting units, which arc shaped parts are preferably approximately concentric with the axis of rotation of the transverse rod D, the movable grate bar can be swung from its normal fire supporting posi tion as shown in Fig. 3, into the fire advane ing positions shown at the left in Fig. l, the axis of rotation of the movable grate bars being such that the fire supporting parts of these bars can swing over the upper surface of the stationary bars to positively advance the fuel. In the construction shown in Figs. 2 l, four of these movable grate bars are shown, which are arranged to operate in groups of two, the rear two of the movable grate bars being preferably first actuated to move the fire toward the rear of the grate and the front two are then actuated to advance the fire toward the rear grate bars. Any other arrangement of the grate bars may, however, be provided.

The swinging of the movable grate bars ifnay be accomplished in any desired manner, the actuating mechanism shown including a downwas y extending arm H secured to each transversely extending rod D and the adjacent pairs of arms H are connected by means of links /z To each of these links is connected an actuating rod 1'. having a part extending through the front wall of the furnace and pivotally connected to an operating lover I which is pivoted at 25 so that the .ctuating rods may be drawn forwardly to actuate the movable grate bars by swinging the lever I about its pivot. Any other means for actuating the movable grate members may, however, be employed.

The rear end of the grate is preferably provided with a dumping mechanism also adapted to be actuated from the front of the furnace. This mechanism includes a dumping bar Or member built up of a plurality of fire supporting units K connected together by means of rods 7c. The fire supporting units K preferably incline downwardly and rearwardly from the rear stationary grate member and means are provided for lowering these fire supporting 'members into a position to permit the fire to be dumped into the ash pit. For this purpose the dumping bar is provided with a downwardly extending bracket which may be pushed rearwardly to permit the dumping bar to assume the position shown in Fig. 4, in which the ashes or clinkers accumulated thereon are dumped into the ash pit.

The grate described has the advantage that the movable members are adapted to positively advance the fuel step by step from one end of the grate to the other end thereof and consequently the grate can used in such a manner that the fire supporting surface thereof is horizontal. in the use of the grate the levers are actuated to move the grate members for advancing the fuel, after which the front portion of the grate is left practically bare. Sufficient green fuel is placed on the bare portion of the grate to form a substantially level fuel bed. This fresh fuel will then ignite from the top and a slow distillation of the gases will take place, the gases passing over the incandenscent portions of the fire where they will be entirely consumed. In actuating the movable grate members, the rear members are preferably actuated first and the front members last. The movable grate memhere in advancing the fuel, compress the same and in that way eliminate holes or cavities in the fuel bed, and on account of the packed condition of the fuel bed thus produced, a nearly perfect combustion of the fuel takes place. In using the g 'ate in this manner the air from beneath the grate passes through a thin and compact fuel bed practically free from ashes, resulting in a thorough combustion of the gases in the combustion chamber. The grate is also so constructed that it can very readily be taken apart for replacement of burnt out or damaged parts, the stationary grate bars being set into the longitudinal supporting barsin such a manner that it is merely necessary to raise the same out of the recesses a and after the stationary bars are raised outof the recesses, the movable bars may also be removed from the grate. In case it is desired to move and replace a fire supporting element of the stationary grate bar, this can be done without removing the bar from the furnace by sliding the elements lengthwise beyond the end of the head or rib c and then lifting the units out of engagement with the transverse supporting bar B. The fire supporting elements of the movable grate barmay be removed by withdrawing the rods G G. The transverse rods D which support the movable grate bars are arranged at such a distance below'the grate that they are removed from the injurious heat of the fire so that these rods are practically immune from injury.

I claim as my invention:

1. A grate including longitudinalsupporting bars having recesses in the upper portions thereof, stationary grate bars having portions arranged in said recesses, movable grate bars having pivots also arrangedin said recesses below said stationary grate bars, and means for causing said movable grate bars to swing about said pivots over the surfaces of said stationary grate bars. V I

A grate including longitudinal supporting bars having recesses in. the upper portions thereof, movable grate bars having pivots arranged in the bottoms of said recesses, and stationary grate bars having portions extending into said recesses and confining said pivots in the lower portions of said recesses.

3. A grate including longitudinal supporting bars having recesses in the upper portions thereof, stationary grate bars having portions arranged in said recesses, supporting pivot rods supported in said recesses below said stationary bars, movable grate bars, and arms arranged below said grate and connecting said movable grate bars and said rods. 7

4L. Agrate including a stationary grate bar, a movable grate bar arranged adjacent to said stationary grate bar and adapted when in its normal position to form with said stationary grate bar a substantially flat grate surface, said movable gratebar including an arm pivoted at one end below said stationary grate bar and having at the other end thereof an are shaped upwardly extending portion, the upper end of which forms a fuel supporting and pushing surface, and a plurality of fuel supporting and pushing units, the curvature of said arc-shaped portion and said units being substantially concentric with the pivotal axis of said arms.

5. A grate including longitudinal supporting bars, alternately arranged stationary and movable grate bars mounted on said supporting bars forming a fuel supporting surface therefor, said movable grate bars being provided with fuel supporting and pushing surfaces and including arcuate portions extending from one side of the grate to the other and from the fuel supporting and pushing surfaces thereof to the stationary bars when in any operated position, a plurality of rods, arms extending substantially radially from said portions andcon'nected with said rods, each of said rods being pivotally mounted on said longitudinal supporting bars below said stationary grate bars, and means for turning said rods about their pivotal axis tov cause said movable grate bars'to swing upwardly and forwardly over the stationary grate bars to advance the fuel thereover.

6. In a stoker, stationary and pivoted grate bars arranged in alternation to form a continuous fuel supporting surface each pivoted bar having front and rear arcuate surfaces substantially coaxial with the pivots of said bars, and means for rocking said pivoted bars to cause their fuel supporting faces to travel approximately from edge to edge across the faces of the stationary bars andv closely adjacent thereto to force the fuel along the surface of the, grate.

7. In a mechanical stoker a series of pivoted grate-bars, a frame supporting the bars, bearings in said frame for the pivots of said bars, and stationary grate bars interposed between the pivoted bars and coacting with said bearings to hold the pivots in place.

8. In a stoker a grate including alternately-arranged stationary and movable grate bars which normally form a substantially continuous flat grate surface, said movable bars having fuel pushing surfaces, means for rocking said movable bars to move their fuel pushing surfaces over the stationary bars, said movable bars having arcuate surfaces extending from said pushing surfaces to the surface of the stationary bars when in any operated position for supporting the fuel and preventing it from passing through the grate when said movable bars are actuated.

OLAF W. PETERSEN. 

